Slide-valve



(Model.)' w B, TUBMAN- SLIDE VALVE.

wmmssns ATTORNEYS.

UNITED STATES PATENT OFFICE.

WILLIAM B. TUBMAN, OF WALDRON, ARKANSAS.

'- SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 250,176, dated November 29, 1881..

Application filed August 16, 1881.

To all whom "it may concern Be it known that I, WILLIAM B. TUBMAN, of Waldron, in the county of Scott and State of Arkansas, have invented a new and Improved Balanced Slide-Valve, of which the following is a full, clear, and exact description.

The invention consists in the combination, with the steam-chest provided with supply and exhaust ports, guide-strips, and adjustable pack-strips, of a valve provided with an entrance-port, interior steam-chamber, exhaustports, an opening between the exhaust-ports, and projections on its top and one side, as will be hereinafter fully described;

In the accompanying drawings, Figure 1 is a plan of the improved valve in position in a steam-chest, the cover of the chest being removed. Fig. 2 is a longitudinal sectional elevation of the same on line a m, Fig. 1. Fig. 3 is a transverse sectional elevation of the same on line y y, Fig. 1.

Similar letters of reference indicate corresponding parts.

In the drawings, A represents the steamchest, required to be set on the steam-cylinder, (not shown,) and to have its ports a a correspond with those in said cylinder at either end thereof, whereby steam may be supplied and exhausted. Said chest A is provided on one side with a steam-supply port, I), and on the opposite side with a steam-exhaust port, 0, and on the inside of its top or cover, along the central line thereof, is fixed a box, d, in which is a packing-strip,f, that is adjusted by setscrews 9 g and half-elliptic springs h it against the valve B, to regulate the pressure of the latter on its seat; and on the inside of the exhaust side of the steam-chest A another packing-strip, k, is adjustably held in braces Z, and

(ModeL) steam, communicating with its hollow interior 1), and this interior chamber, p,-terminates at each end in a port, q, in the valve-face. Between these ports q the under face of the valve B is cut away, as shown at s, to reduce the friction-surface upon the valve-seat, and to permitthe escape of exhaust-steam from the steamcylinder when used on the common three-port valve-seat.

On the top and one side of the valve B are formed longitudinal ridges t t, for the packing bars or stripsflt to bear against. The valverod 0 is passed through a stufling-box, D, on one end of the valve-chest A. Steam is admitted through the valve'chest port 1) into the valve-port o thence out of the valveB through a port, q, into the engine-cylinder, (not shown,) by which the piston (not shown) is driven to the opposite end of the cylinder, and by the action of the eccentric (not shown) the valve B is so moved as to arrive at the same end at or near the same time with the piston, thereby opening the port in the other end of the cylinder to permit the steam to exhaust by the end of the valve B into the steam-chest A, and thence through the steam-chest exhaust-port c, and at the same time permitting steam to enter from the valve B into the cylinder to drive the piston back, whereby theengine is set and kept in full motion.

Having thus described my invention, I claim as new and desire to secure byLetters Patent- In a slide-valve, the combination, with the steam-chest A, provided with the supply and exhaust ports b c, the guide-strips d I, and the adjustable packing-stripsflc on its top and exhaust side, of the valve B, provided with the entranceport 0, interior steam-chamber, p, the exhaust-ports q, the opening 8, and the projections t, substantially as and for the purpose set forth.

WILLIAM BRIGHT TUBMAN.

Witnesses:

J OHN BAWLINGS, WILLIAM J. KING. 

